POE-based synergistic modified TPE preservative film production method and device

Abstract

The application relates to the technical field of high polymer material modification, and discloses a TPE preservative film production method based on POE synergistic modification, which comprises the following steps: placing POE, an initiator and a polar grafting monomer in a mixing equipment to perform a melt grafting reaction, so as to obtain a POE-g-polar monomer grafting product; placing the POE-g-polar monomer grafting product, a TPE matrix, a plasticizer and functional additives in a double-screw extruder to perform melt blending, so as to obtain a blended material; performing cooling, granulation and drying treatment on the continuous extrudate of the blended material extruded from the die head of the double-screw extruder in sequence, so as to obtain modified TPE granules; and performing casting film forming, bidirectional stretching treatment and heat setting treatment on the modified TPE granules, so as to obtain a TPE preservative film. The application can improve the compatibility of various components of the TPE preservative film and improve the interface bonding strength.

Description

Technical Field

[0001] This invention relates to a method for producing TPE food preservation film based on POE synergistic modification, belonging to the field of polymer material modification technology. Background Technology

[0002] With the development of the food industry and the increasing awareness of safety among consumers, TPE cling film, as a food contact material, is being used more and more widely in home and commercial settings, which places higher demands on the overall performance of the material.

[0003] In existing technologies, TPE food wrap is mostly produced by mechanical blending. Although this production method is simple and easy to operate, the poor compatibility of the components in the blend system can easily lead to problems with loose interfacial bonding during the melting process, thus affecting the performance of TPE food wrap.

[0004] Therefore, existing technologies lack a solution that can improve the compatibility of the components of TPE food preservation film and enhance the interfacial bonding strength. Summary of the Invention

[0005] This invention provides a method for producing TPE food preservation film based on POE synergistic modification, the main purpose of which is to improve the compatibility of various components of TPE food preservation film and enhance the interfacial bonding strength.

[0006] To achieve the above objectives, the present invention provides a method for producing TPE food preservation film based on POE synergistic modification, the method comprising:

[0007] POE, an initiator, and a polar grafting monomer are placed in a mixing apparatus for a melt grafting reaction to obtain a POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator.

[0008] The POE-g-polar monomer graft compound is melt-blended with TPE matrix, plasticizer and functional additives in a twin-screw extruder to obtain a blended material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix;

[0009] The blended material is extruded from the twin-screw extruder die to form a continuous extrusion. After the continuous extrusion is cooled, pelletized, and dried in sequence, modified TPE granules are obtained. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions.

[0010] The modified TPE granules are subjected to a casting film forming process to form a TPE casting base film. The TPE casting base film is subjected to biaxial stretching treatment, and the biaxially stretched TPE casting base film is subjected to heat setting treatment to obtain a TPE food preservation film.

[0011] Optionally, POE, an initiator, and a polar grafting monomer are placed in a mixing apparatus for a melt grafting reaction to obtain a POE-g-polar monomer graft, comprising:

[0012] The POE and the polar grafted monomer are premixed to obtain a premixed material;

[0013] The premixed material and the initiator are added to the mixing equipment, and the temperature of the mixing equipment is set to increase in a gradient to perform melt shearing treatment on the premixed material in the mixing equipment to obtain the grafting reaction product. The mixing equipment is a twin-screw extruder.

[0014] The grafting reaction product is subjected to online devolatilization to remove unreacted polar graft monomers and decomposition byproducts of the initiator, resulting in purified POE-g-polar monomer grafts.

[0015] Optionally, the premixed materials in the mixing equipment are subjected to melt shearing treatment to obtain grafting reaction products, including:

[0016] The mixing equipment is sequentially configured along the extrusion direction of the premixed material as a melting homogenization section, a gradient heating initiation section, a high-temperature grafting section, and a vacuum devouring section;

[0017] In the melting and homogenization section, the premixed material is completely melted and uniformly dispersed with the initiator to obtain a homogenized melt;

[0018] The homogenized melt is subjected to a temperature ramp-up process in the gradient heating initiation section to obtain an activated melt.

[0019] The initiating and activating melt is transported to the high-temperature grafting section, and the grafting reaction temperature is maintained in the high-temperature grafting section so that the polar grafting monomer reacts with the molecular chain of POE to obtain a crude grafted product.

[0020] The crude grafting product is transported to the vacuum devolatilization section, where unreacted monomers and small molecule byproducts are removed to obtain a purified grafting reaction product.

[0021] Optionally, the homogenized melt undergoes a temperature ramp-up process in the gradient heating initiation section to obtain an activated melt, including:

[0022] The homogenized melt is transported to the gradient heating initiation section, and as the temperature of the homogenized melt is continuously increased from below the half-life decomposition temperature of the initiator to the active decomposition temperature, the initiator is controlled to decompose stepwise and continuously generate primary free radicals to obtain an activated melt.

[0023] Optionally, the POE-g-polar monomer graft compound is melt-blended with a TPE matrix, plasticizer, and functional additives in a twin-screw extruder to obtain a blend material comprising:

[0024] The POE-g-polar monomer graft, the TPE matrix, the plasticizer, and the functional additives are added to a high-speed mixer in a preset ratio for premixing to obtain a premixed material.

[0025] The premixed material is fed to the main feed port of the twin-screw extruder for melt plasticization and shear dispersion to obtain a melt blend system.

[0026] The melt blend system is homogenized in the dispersion section of the twin-screw extruder to ensure that the plasticizer and the functional additives are uniformly distributed in the TPE matrix, thereby obtaining a homogenized TPE blend.

[0027] The homogenized TPE blend is extruded from the twin-screw extruder die to obtain the blend material.

[0028] Optionally, after sequentially performing the cooling, pelletizing, and drying processes on the continuous extruder, modified TPE pellets are obtained, comprising:

[0029] The continuous extrudate is subjected to a cooling and shaping treatment to transform it from a viscous flow state into a solid continuous body. The cooling and shaping treatment is performed using air cooling.

[0030] The cooled solid continuous material is conveyed to a pelletizing device for cutting to obtain discrete pellets. The pelletizing device consists of a traction mechanism, a pressure roller assembly, a rotary cutter and a discharge screen.

[0031] After drying the discrete granules using a hot air drying oven, modified TPE granules are obtained.

[0032] Optionally, the modified TPE granules are subjected to a casting film forming process to form a TPE cast base film, comprising:

[0033] The modified TPE granules are fed to a casting machine and melted and plasticized by the casting machine to form a sheet-like melt film. The casting machine includes a single screw extruder, a T-die, a cooling roller assembly, a thickness gauge, an edge trimming device, and a winding device.

[0034] The sheet-like melt film is cast onto the surface of a cooling roller to cool and shape the sheet-like melt film into a TPE cast base film.

[0035] Optionally, the TPE cast base film is subjected to biaxial stretching treatment, including:

[0036] The TPE cast base film is longitudinally stretched to obtain a uniaxially stretched film.

[0037] The uniaxially stretched film is then stretched laterally to obtain a biaxially stretched film.

[0038] Optionally, the biaxially stretched TPE cast base film is subjected to heat setting treatment to obtain a TPE food preservation film, comprising:

[0039] The biaxially stretched TPE cast base film is subjected to a first-stage heat setting treatment under constant tension to obtain a first-stage heat-set film.

[0040] The primary heat-set film is subjected to a second heat-set process under relaxed tension to obtain a secondary heat-set film.

[0041] The secondary heat-set film is cooled and shaped to obtain TPE food preservation film.

[0042] To address the aforementioned problems, the present invention also provides a TPE preservation film production apparatus based on POE synergistic modification, the apparatus comprising:

[0043] The grafting modification module is used to place POE, initiator and polar grafting monomer in a mixing equipment for melt grafting reaction to obtain POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator.

[0044] The blending and granulation module is used to melt-blend the POE-g-polar monomer graft with TPE matrix, plasticizer and functional additives in a twin-screw extruder to obtain a blended material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix;

[0045] The post-processing module is used to extrude the blended material into a continuous extrusion from the twin-screw extruder die, and sequentially perform cooling, pelletizing and drying treatments on the continuous extrusion to obtain modified TPE granules. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions.

[0046] The molding and processing module is used to cast the modified TPE granules into a film to form a TPE cast base film, to perform biaxial stretching on the TPE cast base film, and to perform heat setting on the biaxially stretched TPE cast base film to obtain a TPE food preservation film.

[0047] Compared to the problems described in the background art, the embodiments of the present invention, by placing POE, an initiator, and a polar grafted monomer in a mixing device for a melt grafting reaction, obtain a POE-g-polar monomer graft. This introduces polar functional groups onto the POE molecular chain, improving its interfacial affinity with the non-polar TPE matrix, thereby solving the problems of poor compatibility and phase separation caused by polarity differences during physical blending. Furthermore, the embodiments of the present invention, by placing the POE-g-polar monomer graft with the TPE matrix, plasticizer, and functional additives in a twin-screw extruder for melt blending, obtain a blend material, which can facilitate the achievement of thin films in subsequent casting and biaxial stretching processes. The synergistic improvement of membrane mechanical and barrier properties provides the necessary microstructural basis. In this embodiment, the blend material is continuously extruded from the twin-screw extruder die, facilitating subsequent cooling, shaping, and pelletizing operations. Furthermore, by sequentially performing cooling, pelletizing, and drying treatments on the continuous extrusion, modified TPE granules are obtained, transforming the unstable molten blend into solid granules that are easy to store and transport. Finally, by biaxially stretching the TPE cast film, the polymer molecular chains within the film can be oriented along the stretching direction, thereby improving its mechanical and optical properties. Therefore, this invention can improve the compatibility of the components of TPE food preservation film and enhance interfacial bonding strength. Attached Figure Description

[0048] Figure 1 This is a schematic flowchart of a method for producing TPE food preservation film based on POE synergistic modification according to an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of a twin-screw extruder structure for implementing a method for producing TPE cling film based on POE synergistic modification, according to an embodiment of the present invention.

[0050] Figure 3 A flowchart of the casting machine unit for implementing the TPE preservation film production method based on POE synergistic modification, provided as an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of a module for implementing a TPE preservation film production device based on POE synergistic modification, according to an embodiment of the present invention.

[0052] Figure 5A schematic diagram of a computer device for a method of producing TPE cling film based on POE synergistic modification according to an embodiment of the present invention;

[0053] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0054] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0055] This application provides a method for producing TPE cling film based on POE synergistic modification. The execution entity of this POE synergistic modification TPE cling film production method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application embodiment: a server, a terminal, etc. In other words, the POE synergistic modification TPE cling film production method can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0056] S1. POE, initiator and polar graft monomer are placed in a mixing equipment for melt grafting reaction to obtain POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator.

[0057] In this embodiment of the invention, POE, an initiator, and a polar graft monomer are placed in a mixing device for a melt grafting reaction to obtain a POE-g-polar monomer graft. This can introduce polar functional groups onto the POE molecular chain, improve its interfacial affinity with the non-polar TPE matrix, and thus solve the problems of poor compatibility and phase separation caused by polarity differences during physical blending.

[0058] In detail, the POE is a polyolefin elastomer copolymerized from ethylene and α-olefin, which serves as the matrix material for graft modification in this invention; the initiator refers to a peroxide compound capable of thermal decomposition to generate free radicals, such as dicumyl peroxide, benzoyl peroxide, or di-tert-butyl peroxide; the polar graft monomer refers to a small molecule compound containing carbon-carbon double bonds and polar functional groups, such as maleic anhydride, acrylic acid, glycidyl methacrylate, or butyl acrylate, wherein the polar functional group includes one or more of carboxyl groups, anhydride groups, ester groups, or epoxy groups; the mixing equipment refers to a mixer or twin-screw extruder capable of providing heating and shearing action to melt the polymer and carry out a chemical reaction; the POE-g-polar monomer graft refers to a modified polymer formed by chemically bonding polar graft monomers to the POE molecular chain through a melt grafting reaction.

[0059] As an embodiment of the present invention, POE, an initiator, and a polar grafting monomer are placed in a mixing apparatus for a melt grafting reaction to obtain a POE-g-polar monomer graft, comprising:

[0060] The POE and the polar grafted monomer are premixed to obtain a premixed material;

[0061] The premixed material and the initiator are added to the mixing equipment, and the temperature of the mixing equipment is set to increase in a gradient to perform melt shearing treatment on the premixed material in the mixing equipment to obtain the grafting reaction product. The mixing equipment is a twin-screw extruder.

[0062] The grafting reaction product is subjected to online devolatilization to remove unreacted polar graft monomers and decomposition byproducts of the initiator, resulting in purified POE-g-polar monomer grafts.

[0063] The premixed material refers to the mixture formed by physically mixing the POE and the polar grafted monomer. It should be noted that during the premixing process, at least part of the polar grafted monomer is adsorbed or swollen on the surface and surface layer of the POE. The grafting reaction product refers to the mixture obtained after melt shearing treatment by the twin-screw extruder, which includes POE-g-polar monomer grafts, unreacted polar grafted monomers, and initiator decomposition byproducts. The unreacted polar grafted monomers include free polar grafted monomers and their oligomers remaining in the grafting reaction product. The initiator decomposition byproducts include small molecule organic compounds and their free radical coupling products generated after the initiator is thermally decomposed.

[0064] According to common knowledge in the art, the typical grafting temperature of dicumyl peroxide (DCP) in a twin-screw extruder is usually controlled between 170 and 190°C, where the half-life of DCP at 180°C is approximately 1 minute. For example, if the initiator described in this embodiment is DCP, the temperature gradient can be set as follows: first temperature zone 130°C, second temperature zone 150°C, third temperature zone 170°C, fourth temperature zone 180°C, and fifth temperature zone 175°C. This ensures a smooth heating process from the feed end to the discharge end, guaranteeing stepwise decomposition of the initiator in each zone and preventing uncontrolled grafting reaction due to localized overheating. It should be noted that the first four temperature zones increase in a stepwise manner, with the fifth temperature zone slightly lower than the fourth. This maintains good material flowability while preventing premature condensation of volatiles at the volatilization port at high temperatures.

[0065] Optionally, the premixing treatment of POE and the polar graft monomer includes: adding POE to a high-speed mixer, spraying the polar graft monomer in a mist under stirring conditions, controlling the mixing temperature at 40℃~80℃, and mixing for 5~15 minutes, so that the polar graft monomer is uniformly adsorbed and partially penetrated to the surface of POE to obtain a premixed material; the online devolatilization treatment of the grafting reaction product is completed by setting a vacuum devolatilization port at the end of the twin-screw extruder, and using an external vacuum system under a negative pressure of -0.05~-0.09MPa to volatilize and remove the unreacted polar graft monomer and initiator decomposition byproducts.

[0066] See Figure 2 The figure shown is a schematic diagram of a twin-screw extruder structure for implementing a TPE preservation film production method based on POE synergistic modification according to an embodiment of the present invention. In the figure: 1 is the main machine base, 2 is the barrel, 3 is the side feeding device, 301 is the guide chute, 4 is the vacuum devolatilization device, 401 is the devolatilization port, 402 is the guide shroud, and 5 is the material guide channel. Specifically: the main base 1 serves as the foundation for the entire machine, supporting and ensuring the coaxiality and stability of the equipment; the barrel 2 is the core cavity for material processing, with meshing twin screws inside, achieving POE melting and plasticizing, component mixing, and grafting reaction through segmented temperature control and shearing action; the side feeding device 3 and the guide chute 301 connected to it are used to accurately transport the premixed material to the designated reaction section inside the barrel, and can realize the step-by-step feeding of the initiator to control the initiation process of the grafting reaction; the vacuum devolatilization device 4, the devolatilization port 401, and the guide hood 402 work together, with the devolatilization port serving as the volatile discharge channel, and the guide hood used to guide the flow of volatiles and expand the devolatilization area, removing unreacted monomers, initiator decomposition byproducts, and small molecule impurities through an external vacuum system, achieving online purification of the product; the material guide channel 5 connects the discharge end and the feed end of the barrel, used to return some material to the front shearing area to extend the reaction time, improve the grafting rate, and enhance the mixing uniformity.

[0067] As an optional embodiment of the present invention, the premixed material in the twin-screw extruder is subjected to melt shearing treatment to obtain grafting reaction products, including:

[0068] The mixing equipment is sequentially configured along the extrusion direction of the premixed material as a melting homogenization section, a gradient heating initiation section, a high-temperature grafting section, and a vacuum devouring section;

[0069] In the melting and homogenization section, the premixed material is completely melted and uniformly dispersed with the initiator to obtain a homogenized melt;

[0070] The homogenized melt is subjected to a temperature ramp-up process in the gradient heating initiation section to obtain an activated melt.

[0071] The initiating and activating melt is transported to the high-temperature grafting section, and the grafting reaction temperature is maintained in the high-temperature grafting section so that the polar grafting monomer reacts with the molecular chain of POE to obtain a crude grafted product.

[0072] The crude grafting product is transported to the vacuum devolatilization section, where unreacted monomers and small molecule byproducts are removed to obtain a purified grafting reaction product.

[0073] The melting homogenization section is a barrel section in the twin-screw extruder where the temperature is set above the melting point of POE but below the initial decomposition temperature of the initiator. The gradient heating initiation section is a barrel section in the twin-screw extruder located downstream of the melting homogenization section, where the temperature continuously increases from below the half-life decomposition temperature of the initiator to the active decomposition temperature, used to control the stepwise decomposition of the initiator through temperature ramping. The high-temperature grafting section is a barrel section in the twin-screw extruder located downstream of the gradient heating initiation section, where the temperature is maintained at a constant grafting reaction temperature, used to provide a reaction site for the covalent bonding of the polar graft monomer with the POE molecular chain. The vacuum devolatilization section is a barrel section at the end of the twin-screw extruder connected to a vacuum system, used to remove volatiles under negative pressure. The grafting reaction temperature is sufficient to allow the... The initiator continuously generates free radicals and maintains the temperature range within which the polar grafting monomer and the POE molecular chain undergo a grafting reaction. The free radicals are active intermediates with unpaired electrons generated after the initiator is thermally decomposed, used to capture hydrogen atoms from the POE molecular chain to form active grafting sites. The POE molecular chain is an ethylene-octene copolymer backbone and its side chains, and the polar grafting monomer is covalently linked to the carbon atoms of the backbone or side chains. The unreacted monomers are the aforementioned free polar grafting monomers remaining in the crude grafting product that did not participate in the grafting reaction and their self-polymerized oligomers. The unreacted small molecule byproducts include organic compound residues generated after the thermal decomposition of the initiator, free radical coupling products, and volatile organic compounds generated from the thermal degradation of the polar grafting monomers.

[0074] Further, the homogenized melt undergoes a temperature ramp-up process in the gradient heating initiation section to obtain an activated melt, including:

[0075] The homogenized melt is transported to the gradient heating initiation section, and as the temperature of the homogenized melt is continuously increased from below the half-life decomposition temperature of the initiator to the active decomposition temperature, the initiator is controlled to decompose stepwise and continuously generate primary free radicals to obtain an activated melt.

[0076] The half-life decomposition temperature refers to the temperature at which the initiator has a half-life of 1 minute under given conditions. In this embodiment, it can be used to characterize the thermal stability of the initiator and serve as a reference point for the starting temperature of the temperature ramp-up process. The active decomposition temperature refers to the upper limit of the temperature range at which the initiator can continuously generate primary free radicals at a rate sufficient to initiate the grafting reaction within the shear field and reaction time of the twin-screw extruder. The primary free radicals are active intermediates with unpaired electrons generated by the initiator in the early stage of thermal decomposition.

[0077] Optionally, the specific process of controlling the stepwise decomposition of the initiator and the continuous generation of primary free radicals is as follows: In the initial stage of the temperature ramp-up treatment, the temperature of the homogenized melt is lower than the half-life decomposition temperature of the initiator, and the initiator decomposes only a small amount to generate trace amounts of primary free radicals, which are used to induce the formation of pre-grafted structures on the POE molecular chain; as the temperature continues to rise and crosses the half-life decomposition temperature, the decomposition rate of the initiator accelerates, the amount of primary free radicals generated gradually increases, and they continuously attack the POE molecular chain to form grafting active sites and initiate chain growth reactions; when the temperature of the homogenized melt reaches the active decomposition temperature, the decomposition rate of the initiator reaches its maximum value and maintains a dynamic equilibrium in the high-temperature grafting section, realizing a continuous supply of primary free radicals until the initiator is consumed, thereby completing the grafting reaction between the polar grafting monomer and the POE molecular chain.

[0078] S2. The POE-g-polar monomer graft compound, TPE matrix, plasticizer and functional additives are placed in a twin-screw extruder for melt blending to obtain a blended material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix.

[0079] In this embodiment of the invention, the POE-g-polar monomer graft is melt-blended with TPE matrix, plasticizer and functional additives in a twin-screw extruder to obtain a blended material, which can provide the necessary microstructure basis for achieving synergistic improvement of film mechanical properties and barrier properties in subsequent casting and biaxial stretching processes.

[0080] Specifically, the TPE matrix refers to styrene-ethylene-butene-styrene block copolymer (SEBS), which is a hydrogenated product of styrene-butadiene-styrene block copolymer (SBS); the plasticizer is a small molecule or oligomer compound used to reduce the melt viscosity of the TPE matrix, improve processing fluidity and film flexibility, preferably food-grade white oil, but naphthenic oil or liquid paraffin may also be used; the functional additive is one of antioxidants, lubricants and antiblocking agents, used to improve the processing stability, performance and shelf life of the film.

[0081] It should be noted that the SEBS molecular structure contains relatively polar polystyrene segments and non-polar ethylene-butene segments. The polar functional groups introduced into the POE-g-polar monomer graft, such as maleic anhydride, can form hydrogen bonds with the polystyrene segments in SEBS, thereby improving the interfacial bonding strength between the two phases, rather than simply grafting polar POE and directly blending it with the non-polar SEBS matrix.

[0082] As an embodiment of the present invention, the POE-g-polar monomer graft compound is melt-blended with a TPE matrix, plasticizer, and functional additives in a twin-screw extruder to obtain a blend material comprising:

[0083] The POE-g-polar monomer graft, the TPE matrix, the plasticizer, and the functional additives are added to a high-speed mixer in a preset ratio for premixing to obtain a premixed material.

[0084] The premixed material is fed to the main feed port of the twin-screw extruder for melt plasticization and shear dispersion to obtain a melt blend system.

[0085] The melt blend system is homogenized in the dispersion section of the twin-screw extruder to ensure that the plasticizer and the functional additives are uniformly distributed in the TPE matrix, thereby obtaining a homogenized TPE blend.

[0086] The homogenized TPE blend is extruded from the twin-screw extruder die to obtain the blend material.

[0087] Specifically, the preset proportions are as follows: the POE-g-polar monomer grafted compound accounts for 5% to 30% of the total mass of the blended materials, the TPE matrix accounts for 50% to 80%, the plasticizer accounts for 10% to 30%, and the functional additives account for 0.5% to 5%. The high-speed mixer is equipped with a stirring device and a temperature control device to achieve macroscopic uniform distribution of each component under solid conditions. The dispersion section refers to the barrel section of the twin-screw extruder located downstream of the melting section and upstream of the metering section. This section is equipped with high-shear mixing elements to break down and disperse the plasticizer and functional additives into the continuous phase of the TPE matrix.

[0088] Optionally, the specific process of conveying the premixed material to the main feed port of the twin-screw extruder for melt plasticization and shear dispersion is as follows: the premixed material is continuously fed into the barrel of the twin-screw extruder through the main feed port, and enters the melting section under the rotational conveying action of the screw; in the melting section, the temperature is controlled to be higher than the melting temperature of the TPE matrix, so that the premixed material gradually changes from a solid state to a molten state under the combined action of external heating and screw shearing heat generation, forming a continuous melt; at the same time, the shearing action of the screw initially mixes the POE-g-polar monomer graft with the TPE matrix, and allows the plasticizer to begin to penetrate into the matrix, obtaining a multi-component melt blend system; the melt blend system is then processed in the twin-screw extruder... The homogenization process in the dispersion section includes: conveying the melt blend system to the dispersion section, where the plasticizer and functional additives are reduced to submicron size through the strong shearing and stretching action of high-shear elements such as kneading blocks, toothed discs, or eccentric triangular prisms; simultaneously, utilizing the localized high pressure formed by the high material filling degree in the dispersion section, the plasticizer is forced to permeate and swell into the molecular chains of the TPE matrix, promoting the uniform distribution of the functional additives in the matrix; finally, by maintaining the temperature of the dispersion section at 10°C to 30°C above the melting temperature of the TPE matrix and maintaining the screw speed at a suitable shear rate, the viscosity, component concentration, and temperature of the melt blend system tend to be uniform, resulting in a homogenized TPE blend.

[0089] S3. The continuous extrusion of the blended material is extruded from the die of the twin-screw extruder. After the continuous extrusion is cooled, pelletized and dried in sequence, modified TPE granules are obtained. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions.

[0090] In this embodiment of the invention, the blended material is extruded continuously from the die of the twin-screw extruder, which facilitates subsequent cooling, shaping and pelletizing operations. The continuous extrudate is a melt strip with a uniform cross-sectional shape. It leaves the die in a continuous state under traction and is rapidly solidified by air cooling to fix its internal microstructure formed by POE-g-polar monomer graft and TPE matrix.

[0091] Furthermore, in this embodiment of the invention, after sequentially performing cooling, pelletizing and drying treatments on the continuous extruder, modified TPE granules are obtained. This can transform the unstable molten blend into solid granules that are easy to store and transport. The modified TPE granules are granular thermoplastic elastomer composite materials containing POE-g-polar monomer grafts, TPE matrix, plasticizers and functional additives, obtained through melt blending and post-treatment.

[0092] As an embodiment of the present invention, after sequentially performing cooling, pelletizing, and drying treatments on the continuous extruder, modified TPE pellets are obtained, comprising:

[0093] The continuous extrudate is subjected to a cooling and shaping treatment to transform it from a viscous flow state into a solid continuous body. The cooling and shaping treatment is performed using air cooling.

[0094] The cooled solid continuous material is conveyed to a pelletizing device for cutting to obtain discrete pellets. The pelletizing device consists of a traction mechanism, a pressure roller assembly, a rotary cutter and a discharge screen.

[0095] After drying the discrete granules using a hot air drying oven, modified TPE granules are obtained.

[0096] It should be noted that in the modified TPE granules, the POE-g-polar monomer graft material is uniformly distributed in the TPE matrix in the form of micro-regions. Specifically, during the melt blending process, the POE-g-polar monomer graft material, as a dispersed phase, is dispersed into micron-sized particles under the shearing action of a twin-screw extruder, and exists stably in the continuous phase formed by the TPE matrix in the form of independent micro-regions, with the particle size range of the micro-regions being 0.5~5μm.

[0097] S4. The modified TPE granules are subjected to casting film formation treatment to form a TPE casting base film. The TPE casting base film is subjected to biaxial stretching treatment, and the biaxially stretched TPE casting base film is subjected to heat setting treatment to obtain TPE preservation film.

[0098] In this embodiment of the invention, the modified TPE granules are cast into a film to form a TPE cast base film. The rapid cooling characteristics of the cast film can freeze the micro-dispersion structure of the POE-g polar monomer graft in the TPE matrix, thereby ensuring the interfacial bonding strength and performance stability of the material during subsequent processing. The TPE cast base film is a sheet-like solid intermediate product with a flat surface and uniform thickness. Its interior retains the microstructure characteristics of the POE-g polar monomer graft uniformly distributed in the TPE matrix in the form of micro-regions, and can be directly used for subsequent biaxial stretching treatment.

[0099] As an embodiment of the present invention, the modified TPE granules are subjected to a casting film forming process to form a TPE casting base film, including:

[0100] The modified TPE granules are fed to a casting machine and melted and plasticized by the casting machine to form a sheet-like melt film. The casting machine includes a single screw extruder, a T-die, a cooling roller assembly, a thickness gauge, an edge trimming device, and a winding device.

[0101] The sheet-like melt film is cast onto the surface of a cooling roller to cool and shape the sheet-like melt film into a TPE cast base film.

[0102] In detail, the single-screw extruder is used to melt and plasticize the modified TPE granules and convey them to a T-die. The T-die has a coat hanger-type flow channel design to evenly distribute the melt and extrude it into a thin sheet-like melt film of uniform width. The cooling roller group typically consists of 1 to 3 mirror rollers with internal circulating cooling water to rapidly cool and solidify the high-temperature melt film, forming a TPE cast base film with a smooth surface. The thickness gauge is used to monitor the film thickness distribution online. The edge trimming device is used to remove unevenly thick edges on both sides of the film. The winding device is used to wind the shaped film into a roll.

[0103] Specifically, see Figure 3 The diagram shows the workflow of the casting machine. First, the dried modified TPE granules are added to a single-screw extruder. The extruder is sequentially configured with a feeding section, compression section, metering section, and homogenization section along the material conveying direction. The temperatures of each section are controlled at 140~160℃, 160~180℃, 180~200℃, and 190~210℃ respectively, allowing the granules to gradually melt. Then, the screw speed is adjusted to 80~150 rpm, causing the melt to plasticize and homogenize under shearing, forming a polymer melt with stable viscosity. This melt is then conveyed to the T-die under the screw thrust. At this point, the die temperature is controlled to be the same as or slightly higher than the homogenization section temperature by 5~10℃. After entering the T-die, the melt flows evenly along the width of the die through a coat hanger-type flow channel. The extrusion rate is controlled by adjusting the die lip gap, ultimately forming a thin sheet-like melt film. This sheet-like melt film is then cast onto the surface of a cooling roller assembly. After rapid cooling and shaping by the cooling rollers, a TPE cast base film with low crystallinity is formed. This low-crystallinity TPE cast base film has good ductility and tensile orientation capabilities, providing favorable conditions for subsequent biaxial stretching processing. After leaving the cooling roller assembly, the TPE cast base film enters a thickness gauge for online thickness monitoring. The thickness gauge feeds back the thickness data to the extruder and T-die to adjust the extrusion rate and die lip gap to control the film thickness uniformity. Finally, the film first enters a trimming device to remove the two side edges, and then is wound into a roll by a winding device to obtain the finished TPE cast base film roll.

[0104] Furthermore, in this embodiment of the invention, by subjecting the TPE cast base film to biaxial stretching treatment, the polymer molecular chains inside the film can be oriented and aligned along the stretching direction, thereby improving its mechanical and optical properties.

[0105] As an embodiment of the present invention, the TPE cast base film is subjected to biaxial stretching treatment, including:

[0106] The TPE cast base film is longitudinally stretched to obtain a uniaxially stretched film.

[0107] The uniaxially stretched film is then stretched laterally to obtain a biaxially stretched film.

[0108] It should be noted that during the longitudinal and transverse stretching of the TPE cast base film, the stretching temperature is controlled within a range higher than the glass transition temperature of the TPE matrix but lower than its melting temperature. The glass transition temperature refers to the temperature at which the amorphous segments in the TPE matrix transition from a glassy state to a highly elastic state. For example, the longitudinal stretching temperature can be set to 70~90℃, and the transverse stretching temperature can be set to 80~100℃.

[0109] In this embodiment of the invention, a TPE food preservation film is obtained by heat-setting the biaxially stretched TPE cast base film. This process allows the molecular chain structure inside the film to relax and rearrange, eliminating the internal stress generated during biaxial stretching and thus improving the dimensional stability of the film.

[0110] As an embodiment of the present invention, the TPE cast base film after biaxial stretching is subjected to heat setting treatment to obtain a TPE food preservation film, comprising:

[0111] The biaxially stretched TPE cast base film is subjected to a first-stage heat setting treatment under constant tension to obtain a first-stage heat-set film.

[0112] The primary heat-set film is subjected to a second heat-set process under relaxed tension to obtain a secondary heat-set film.

[0113] The secondary heat-set film is cooled and shaped to obtain TPE food preservation film.

[0114] For example, the first heat-setting process of the biaxially stretched TPE cast base film under constant tension includes: firstly, setting the heat-setting temperature of the biaxially stretched TPE cast base film to 80~100℃ and the heat-setting time to 5~15 seconds; during the heat-setting process, allowing the film to shrink by 3%~8% in the longitudinal or transverse direction, thus completing the second heat-setting in a relaxed state, resulting in a second heat-set film. The specific process of cooling and setting the second heat-set film includes: rapidly cooling the second heat-set film to below 50℃ at a cooling rate of 10~30℃ / s, quickly freezing the relaxed state of its molecular chains to prevent further shrinkage during slow cooling, resulting in a TPE preservation film. The cooling method can be one of air cooling, roller cooling, or air cooling.

[0115] The constant tension refers to the constant tension on the film in the longitudinal and transverse directions during the heat setting process, without shrinkage or expansion of the film size; the relaxed tension refers to allowing the film to shrink to a certain extent under reduced tension conditions during the heat setting process, with the shrinkage rate controlled within a preset range; the primary heat-set film refers to the TPE film intermediate product whose internal stress is initially released after the first stage of heat setting treatment; the secondary heat-set film refers to the TPE film intermediate product whose internal stress is further eliminated and whose molecular chains reach thermodynamic equilibrium after the second stage of heat setting treatment; the TPE food preservation film refers to a thermoplastic elastomer film with good dimensional stability and mechanical properties obtained after biaxial stretching and segmented heat setting treatment, such as TPE food preservation film.

[0116] To verify the effectiveness of this invention in improving the compatibility of TPE food preservation film components, enhancing interfacial bonding strength, and thus solving the problems of poor component compatibility, weak interfacial bonding, and insufficient mechanical and optical properties caused by traditional mechanical blending methods, the following comparative experiment was designed:

[0117] The experimental group strictly followed the method described in this invention, with the following specific process parameters: POE-g-polar monomer grafts with a grafting rate of 1.2% were used, accounting for 15 wt% of the total TPE cling film mass; SEBS was selected as the TPE matrix, accounting for 65 wt%; white oil was selected as the plasticizer, accounting for 18 wt%; and antioxidant 1010 and a slip agent were selected as functional additives, totaling 2 wt%. The above raw materials were melt-blended and granulated using a twin-screw extruder, and the resulting granules were vacuum-dried at 80°C for 4 hours for later use. The specific process includes: adding dried granules into a single-screw extruder for casting; setting the temperatures of each section of the extruder as follows: feeding section 150℃, plasticizing section 170℃, homogenizing section 180℃, and die head 185℃; screw speed 100 rpm; and traction speed 30 m / min to obtain a TPE cast film with a thickness of approximately 25 μm; subjecting the obtained TPE cast film to biaxial stretching treatment, with a longitudinal stretching temperature of 85℃ and a stretching ratio of 4 times; and a transverse stretching temperature of 95℃ and a stretching ratio of 3 times; after stretching, the film undergoes segmented heat setting treatment: the first stage has a setting temperature of 90℃ and a setting time of 10 seconds, during which constant longitudinal and transverse tension is applied to maintain the orientation of the film's molecular chains; the second stage has a setting temperature of 120℃ and a setting time of 20 seconds, during which tension is gradually released to fix the molecular chain orientation structure and prevent thermal shrinkage and springback during subsequent use; and finally, after cooling, the film is wound up to obtain the TPE food preservation film. The traditional control group used the exact same raw material ratios and subsequent processing techniques as the experimental group, only changing the POE modification method to control a single variable. Specifically, ungrafted ordinary POE replaced the POE-g-polar monomer graft described in this invention. The types, mass ratios, melt blending process, stretching process, and segmented heat setting process of the remaining components were all consistent with the experimental group. The control film was obtained after processing using the same procedures. It should be noted that the processing and performance testing of all samples strictly followed current national or international standards. The mechanical property data are the average ± standard deviation of five parallel samples to ensure the statistical reliability of the results. The specific comparative data after standardized testing are as follows:

[0118] Performance indicators experimental group control group Longitudinal tensile strength (MPa) 42.5±1.8 28.6±2.1 Transverse tensile strength (MPa) 38.2±1.6 25.4±1.9 Elongation at break (%) 520±25 450±30 Haze (%) 3.2±0.2 6.8±0.5 Light transmittance (%) 89.5±0.5 86.7±0.6 Puncture resistance (N) 8.6±0.4 5.2±0.4 Longitudinal thermal shrinkage rate (%, 120℃×10min) 2.8±0.3 4.5±0.5 Transverse thermal shrinkage rate (%, 120℃×10min) 1.9±0.2 3.2±0.4 Scanning electron microscopy (SEM) cross-sectional morphology The cross-section is smooth and dense. The POE-g-polar monomer graft is uniformly dispersed in the SEBS matrix in the form of micro-regions. The micro-regions are tightly bonded to the matrix interface with no obvious debonding phenomenon, and the two phases have good compatibility. The cross-section is rough and porous, with obvious debonding of the two-phase interface, pores, and POE particle agglomeration, indicating weak interfacial bonding. Dynamic mechanical analysis (DMA) compatibility characterization The loss factor peak is single and has a regular shape with no obvious splitting, indicating excellent compatibility between the two phases and tight interfacial bonding. The loss factor peak splits into two independent peaks, indicating poor bonding between the two phases and poor compatibility.

[0119] SEM image analysis of the experimental group film cross-section showed that the particle size distribution of the POE-g-polar monomer graft microregions ranged from 0.8 to 3.5 μm, with an average particle size of 1.6 μm and an average spacing of about 7 μm between adjacent microregions, which is consistent with the microstructure characteristics described in this invention. SEM testing was performed using a Hitachi S-4800 field emission scanning electron microscope with an accelerating voltage of 5 kV. The samples were subjected to liquid nitrogen embrittlement followed by gold sputtering. DMA testing was performed using a TA Q800 dynamic mechanical analyzer with a testing frequency of 1 Hz, a heating rate of 3 °C / min, and a temperature range of -80 °C to 150 °C.

[0120] Conclusion: Comparison of the above control test data shows that the TPE preservation film prepared using the POE-g-polar monomer graft described in this invention exhibits the following advantages: longitudinal tensile strength reaches 42.5 MPa, a 48% increase compared to the control group's 28.6 MPa; puncture resistance reaches 8.6 N, a 65% increase compared to the control group's 5.2 N; elongation at break reaches 520%, a 15.6% increase compared to the control group's 450%; haze decreases to 3.2%, a 53% decrease compared to the control group's 6.8%; light transmittance reaches 89.5%, a 2.8 percentage point increase compared to the control group's 86.7%; and longitudinal heat shrinkage rate decreases to 2.8%, a 38% decrease compared to the control group's 4.5%. The transverse thermal shrinkage rate was reduced to 1.9%, a 41% decrease compared to the control group's 3.2%. All performance indicators were significantly better than the control group, indicating that the TPE preservation film prepared by this invention has significantly improved mechanical properties, optical properties, and dimensional stability. Scanning electron microscopy observation and dynamic mechanical analysis results show that the above performance improvement is due to the POE melt grafting modification of this invention, which allows the POE-g-polar monomer graft to be uniformly dispersed in the SEBS matrix in the form of micro-regions. The two-phase interface is tightly bonded, effectively solving the problem of interface debonding and agglomeration caused by the poor compatibility between non-polar POE and polar SEBS in the traditional mechanical blending method.

[0121] like Figure 4 The diagram shown is a functional block diagram of a TPE preservation film production device based on POE synergistic modification according to the present invention.

[0122] The TPE food preservation film production device 400 based on POE synergistic modification described in this invention can be installed in an electronic device. Depending on the functions to be implemented, the TPE food preservation film production device based on POE synergistic modification includes a grafting modification module 401, a blending and granulation module 402, a post-processing module 403, and a molding and processing module 404. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and is stored in the memory of the electronic device.

[0123] In this embodiment of the invention, the functions of each module / unit are as follows:

[0124] The grafting modification module 401 is used to place POE, initiator and polar grafting monomer in a mixing equipment for melt grafting reaction to obtain POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator.

[0125] The blending and granulation module 402 is used to melt-blend the POE-g-polar monomer graft with the TPE matrix, plasticizer and functional additives in a twin-screw extruder to obtain a blended material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix;

[0126] The post-processing module 403 is used to extrude the blended material into a continuous extrusion from the twin-screw extruder die. After sequentially performing cooling, pelletizing and drying treatments on the continuous extrusion, modified TPE granules are obtained. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions.

[0127] The molding and processing module 404 is used to perform casting film processing on the modified TPE granules to form a TPE casting base film, to perform biaxial stretching treatment on the TPE casting base film, and to perform heat setting treatment on the biaxially stretched TPE casting base film to obtain a TPE preservation film.

[0128] In detail, the modules in the TPE preservation film production device 400 based on POE synergistic modification described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The method described herein is the same as the TPE preservation film production method based on POE synergistic modification, and can produce the same technical effect, so it will not be repeated here.

[0129] In one embodiment, a computer device is provided, which may be a server or a client, and its internal structure diagram may be as follows: Figure 5 As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile and / or volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface is used for communication with external clients via a network connection. When executed by the processor, the computer program implements functions or steps on the server or client side of a TPE preservation film production method based on POE co-modification.

[0130] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0131] S1. Place POE, initiator and polar graft monomer in a mixing equipment to carry out a melt grafting reaction to obtain POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator.

[0132] S2. The POE-g-polar monomer graft compound, TPE matrix, plasticizer and functional additives are placed in a twin-screw extruder for melt blending to obtain a blend material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix;

[0133] S3. The continuous extrusion of the blended material is extruded from the die of the twin-screw extruder. After the continuous extrusion is cooled, pelletized and dried in sequence, modified TPE granules are obtained. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions.

[0134] S4. The modified TPE granules are subjected to casting film formation treatment to form a TPE casting base film. The TPE casting base film is subjected to biaxial stretching treatment, and the biaxially stretched TPE casting base film is subjected to heat setting treatment to obtain TPE preservation film.

[0135] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0136] S1. Place POE, initiator and polar graft monomer in a mixing equipment to carry out a melt grafting reaction to obtain POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator.

[0137] S2. The POE-g-polar monomer graft compound, TPE matrix, plasticizer and functional additives are placed in a twin-screw extruder for melt blending to obtain a blend material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix;

[0138] S3. The continuous extrusion of the blended material is extruded from the die of the twin-screw extruder. After the continuous extrusion is cooled, pelletized and dried in sequence, modified TPE granules are obtained. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions.

[0139] S4. The modified TPE granules are subjected to casting film formation treatment to form a TPE casting base film. The TPE casting base film is subjected to biaxial stretching treatment, and the biaxially stretched TPE casting base film is subjected to heat setting treatment to obtain TPE preservation film.

[0140] It should be noted that the functions or steps that can be implemented by the computer-readable storage medium or computer device described above can be referred to the relevant descriptions on the server side and client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.

[0141] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0142] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0143] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0144] Finally, it should be noted that in the above embodiments, each embodiment can be combined with each other or independent. Deleting any one of them will not affect the technical implementation of other embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for producing TPE food preservation film based on POE synergistic modification, characterized in that, The method includes: POE, an initiator, and a polar grafting monomer are placed in a mixing apparatus for a melt grafting reaction to obtain a POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator. The POE-g-polar monomer graft compound is melt-blended with TPE matrix, plasticizer and functional additives in a twin-screw extruder to obtain a blended material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix; The blended material is extruded from the twin-screw extruder die to form a continuous extrusion. After the continuous extrusion is cooled, pelletized, and dried in sequence, modified TPE granules are obtained. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions. The modified TPE granules are subjected to a casting film forming process to form a TPE casting base film. The TPE casting base film is subjected to biaxial stretching treatment, and the biaxially stretched TPE casting base film is subjected to heat setting treatment to obtain a TPE food preservation film.

2. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 1, characterized in that, POE, an initiator, and a polar graft monomer are placed in a mixing apparatus for a melt grafting reaction to obtain a POE-g-polar monomer graft, comprising: The POE and the polar grafted monomer are premixed to obtain a premixed material; The premixed material and the initiator are added to the mixing equipment, and the temperature of the mixing equipment is set to increase in a gradient to perform melt shearing treatment on the premixed material in the mixing equipment to obtain the grafting reaction product. The mixing equipment is a twin-screw extruder. The grafting reaction product is subjected to online devolatilization to remove unreacted polar graft monomers and decomposition byproducts of the initiator, resulting in purified POE-g-polar monomer grafts.

3. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 2, characterized in that, The premixed materials in the mixing equipment are subjected to melt shearing treatment to obtain grafting reaction products, including: The mixing equipment is sequentially configured along the extrusion direction of the premixed material as a melting homogenization section, a gradient heating initiation section, a high-temperature grafting section, and a vacuum devouring section; In the melting and homogenization section, the premixed material is completely melted and uniformly dispersed with the initiator to obtain a homogenized melt; The homogenized melt is subjected to a temperature ramp-up process in the gradient heating initiation section to obtain an activated melt. The initiating and activating melt is transported to the high-temperature grafting section, and the grafting reaction temperature is maintained in the high-temperature grafting section so that the polar grafting monomer reacts with the molecular chain of POE to obtain a crude grafted product. The crude grafting product is transported to the vacuum devolatilization section, where unreacted monomers and small molecule byproducts are removed to obtain a purified grafting reaction product.

4. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 3, characterized in that, The homogenized melt undergoes a temperature ramp-up process in the gradient heating initiation section to obtain an activated melt, comprising: The homogenized melt is transported to the gradient heating initiation section, and as the temperature of the homogenized melt is continuously increased from below the half-life decomposition temperature of the initiator to the active decomposition temperature, the initiator is controlled to decompose stepwise and continuously generate primary free radicals to obtain an activated melt.

5. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 1, characterized in that, The POE-g-polar monomer graft compound is melt-blended with a TPE matrix, plasticizer, and functional additives in a twin-screw extruder to obtain a blend material comprising: The POE-g-polar monomer graft, the TPE matrix, the plasticizer, and the functional additives are added to a high-speed mixer in a preset ratio for premixing to obtain a premixed material. The premixed material is fed to the main feed port of the twin-screw extruder for melt plasticization and shear dispersion to obtain a melt blend system. The melt blend system is homogenized in the dispersion section of the twin-screw extruder to ensure that the plasticizer and the functional additives are uniformly distributed in the TPE matrix, thereby obtaining a homogenized TPE blend. The homogenized TPE blend is extruded from the twin-screw extruder die to obtain the blend material.

6. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 1, characterized in that, After sequentially performing cooling, pelletizing, and drying processes on the continuous extruder, modified TPE pellets are obtained, comprising: The continuous extrudate is subjected to a cooling and shaping treatment to transform it from a viscous flow state into a solid continuous body. The cooling and shaping treatment is performed using air cooling. The cooled solid continuous material is conveyed to a pelletizing device for cutting to obtain discrete pellets. The pelletizing device consists of a traction mechanism, a pressure roller assembly, a rotary cutter and a discharge screen. After drying the discrete granules using a hot air drying oven, modified TPE granules are obtained.

7. The method for producing TPE preservation film based on POE synergistic modification as described in claim 1, characterized in that, The modified TPE granules are subjected to a casting film forming process to form a TPE cast base film, comprising: The modified TPE granules are fed to a casting machine and melted and plasticized by the casting machine to form a sheet-like melt film. The casting machine includes a single screw extruder, a T-die, a cooling roller assembly, a thickness gauge, an edge trimming device, and a winding device. The sheet-like melt film is cast onto the surface of a cooling roller to cool and shape the sheet-like melt film into a TPE cast base film.

8. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 1, characterized in that, The TPE cast base film is subjected to biaxial stretching treatment, including: The TPE cast base film is longitudinally stretched to obtain a uniaxially stretched film. The uniaxially stretched film is then stretched laterally to obtain a biaxially stretched film.

9. The method for producing TPE food preservation film based on POE synergistic modification as described in claim 1, characterized in that, The TPE cast base film after biaxial stretching is subjected to heat setting treatment to obtain TPE food preservation film, comprising: The biaxially stretched TPE cast base film is subjected to a first-stage heat setting treatment under constant tension to obtain a first-stage heat-set film. The primary heat-set film is subjected to a second heat-set process under relaxed tension to obtain a secondary heat-set film. The secondary heat-set film is cooled and shaped to obtain TPE food preservation film.

10. A TPE food preservation film production device based on POE synergistic modification, characterized in that, The apparatus for performing a method for producing a TPE preservation film based on POE synergistic modification as described in any one of claims 1-9 includes: The grafting modification module is used to place POE, initiator and polar grafting monomer in a mixing equipment for melt grafting reaction to obtain POE-g-polar monomer graft, wherein the melt grafting reaction is carried out at a temperature higher than the decomposition temperature of the initiator. The blending and granulation module is used to melt-blend the POE-g-polar monomer graft with TPE matrix, plasticizer and functional additives in a twin-screw extruder to obtain a blended material, wherein the melt blending temperature is higher than the melting temperature of the TPE matrix; The post-processing module is used to extrude the blended material into a continuous extrusion from the twin-screw extruder die, and sequentially perform cooling, pelletizing and drying treatments on the continuous extrusion to obtain modified TPE granules. The POE-g-polar monomer graft in the modified TPE granules is uniformly distributed in the TPE matrix in the form of micro-regions. The molding and processing module is used to cast the modified TPE granules into a film to form a TPE cast base film, to perform biaxial stretching on the TPE cast base film, and to perform heat setting on the biaxially stretched TPE cast base film to obtain a TPE food preservation film.

Images